SMASH Monsters - City Rampage is an online mobile game, strategy game, build its defenses, vaporize intruders, and make money to fund your benevolent research, is free to play on Android and iOS devices, from A Thinking Ape.
Download the game at:
https://play.google.com/store/apps/details?id=ata.squid.smash
https://itunes.apple.com/us/app/smash-monsters-city-rampage/id931130399?mt=8